以下是关于Html.RenderPartial 报错的问题，具体该怎么解决呢》？

Question

说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。

源错误:

行 24: </div>--%>
行 25:
行 26: <% Html.RenderPartial("Header.ascx"); %>
行 27:
行 28: </div>

源文件: e:\gz_project\VS2008\Design\Design.Web\U\UserDomains\Home.aspx 行: 26

堆栈跟踪:

[NullReferenceException: 未将对象引用设置到对象的实例。]
System.Web.Mvc.Html.RenderPartialExtensions.RenderPartial(HtmlHelper htmlHelper, String partialViewName) +10
ASP.u_userdomains_home_aspx.__Renderform1(HtmlTextWriter __w, Control parameterContainer) in e:\gz_project\VS2008\Design\Design.Web\U\UserDomains\Home.aspx:26
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +256
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) +163
System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +32
System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) +51
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) +40
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.Page.Render(HtmlTextWriter writer) +29
System.Web.Mvc.ViewPage.Render(HtmlTextWriter writer) +59
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1266

Answer 1

如果你的partial（本例中也就是Header.ascx）是在当前请求的controller下（也就是位于目录/Views/nameController下）或共享目录下（也就是/Views/Shared下），那么你只要把后缀.ascx去掉就行了，也就是把你的第26行换成<% Html.RenderPartial("Header.ascx"); %>。如果你的partial位于其它位置，那么你需要引用全虚拟目录，目录依你项目而定，形式如下：<%: Html.Partial("~/Views/Shared/Partials/MyOtherPartial.ascx") %>注意，这个时候需要.ascx后缀。